Obama will use his speech at a U.N. summit Tuesday to announce plans to sign an executive order requiring the U.S. government to take climate change into account when it spends money overseas to help poorer countries, the White House said. The U.S. will also offer vulnerable communities abroad new tools to address the effects of climate change through science and technology.

The measures join a host of commitments Obama will announce at the summit, where more than 120 world leaders will gather on the sidelines of the U.N. General Assembly to galvanize support for a global climate treaty to be finalized next year in Paris. U.N. Secretary-General Ban Ki-moon, the summit's host, is expecting leaders to come with specific pledges in hand to mitigate climate change, as a way to show they're serious about ambitious emissions reductions in the treaty.

Obama's goals at the summit: to convince other nations that the U.S. is doing its part to curb greenhouse gases, and make the case that other major polluters should step up, too.